Flex Your PCD Mettle:

[Zilch]

Flex It Round #3.1 - EconoWave Delite 10e:

Original large Advent gets QSC 122i 10.25" axisymmetric waveguide and split speaker ring w/T-nuts to mount Eminence Deltalite II 2510:

[Pete Schumacher]

Re: Flex Your PCD Mettle:

that QSC waveguide is not symmetrical? It definitely looks non-uniform by the "sheen" in the pic.

Is this the one in the pic?

http://qsc.stores.yahoo.net/hpr122ihorn.html

[Zilch]

Re: Flex Your PCD Mettle:

that QSC waveguide is not symmetrical? It definitely looks non-uniform by the "sheen" in the pic.

Symmetrical, to the best of my knowledge. We're seeing images of the 4' fluorescent light fixture directly above, looks like.

[I'll find a stopper and fill one with beer to verify. :p ]

Is this the one in the pic?

http://qsc.stores.yahoo.net/hpr122ihorn.html

Yup....

[Pete Schumacher]

Re: Flex Your PCD Mettle:

Symmetrical, to the best of my knowledge. We're seeing images of the 4' fluorescent light fixture directly above, looks like.

[I'll find a stopper and fill one with beer to verify. ;) ]

Yup....

Excellent.

D, Rose is going to be ordering one so that he can "duplicate" it in MDF with his RadarCarve machine.

http://www.radarcarve.net/

He's attempting a two-way using the RS28F and RS225-4.

Are you going to be doing an evaluation of that waveguide loaded with the RS28F?

Do you happen to know the depth of the opening from the front of the flange?

[Zilch]

Re: Flex Your PCD Mettle:

Are you going to be doing an evaluation of that waveguide loaded with the RS28F?

Still in the queue; we'll be getting the baseline here in this thread.

Do you happen to know the depth of the opening from the front of the flange?

Measures 3" exactly.

[If I'm wrong, I'll jus' claim mine are different.... :D ]

[HareBrained]

Dayotn PA Drivers?

Pete or Zilch, any thoughts about using the new Dayton PA drivers in an EconoWave variant? I have yet to fire up Unibox on them but PE is promising a bit deep output, and the cost is very reasonable.

[Zilch]

Re: Flex Your PCD Mettle:

Link us to them, please....

[danklugherz]

Re: Flex Your PCD Mettle:

Link us to them, please....

These are the ones Zilch. http://www.parts-express.com/wizards...ge+Flash+Panel

How would a 15" work with the QSC horn?

[Pete Schumacher]

Re: Flex Your PCD Mettle:

These are the ones Zilch. http://www.parts-express.com/wizards...ge+Flash+Panel

How would a 15" work with the QSC horn?

If the response plot is to be believed, then it would make a great candidate, as would the 18, 12 or 10. They all have reasonable response past 1500Hz, though the 18 would be pushing past the limits of the criteria of constant directivity.

[Zilch]

Re: Flex Your PCD Mettle:

How would a 15" work with the QSC horn?

I've shown two QSC waveguides in this thread, the 14" x 10" 152i, and now this 10.25" 122i.

A prime objective of EconoWave design is matching directivities of the woofer and waveguide in the crossover region. Larger woofers have narrower dispersion at these frequencies than smaller ones, which may be calculated from the piston diameter. A 15" woofer narrows to 90° around 1 kHz, for example. For waveguides, pattern control is also related to size: larger ones control lower.

The larger 90° (horizontal) 152i QSC waveguide has been measured by Augerpro (Brandon) and shown to begin losing pattern control at 2 kHz, and by 1 kHz, it's effectively not constant directivity, i.e., not a good match for a 15" woofer. None of this precludes anyone from building with this combination, and several have; it's just that smaller 12" woofers offer a more optimum matchup.

Next consideration is how low the compression driver will play in combination with how low the waveguide "loads" it. Generally, I try not to exceed the manufacturer's minimum crossover frequency specification, but many argue that those specs are for pro audio use, and there is considerable leeway for home use with derated SPL. This varies with each compression driver/waveguide combination, and the determination is best made using measurements. DE250 is rated at minimum 1.5 kHz, for example, but Geddes runs it on his 15" woofer/waveguide systems below 1 kHz.

Finally is how HIGH the woofer will play competently, and it's a rare 15" that is well behaved above 1.5 kHz AND delivers extended bass. There are exceptions to all of this, but at the extremes of these tradeoffs, some designs are simply not viable, and others, better and more easily accomplished....

[HareBrained]

Re: Flex Your PCD Mettle:

I've shown two QSC waveguides in this thread, the 14" x 10" 152i, and now this 10.25" 122i.

A prime objective of EconoWave design is matching directivities of the woofer and waveguide in the crossover region. Larger woofers have narrower dispersion at these frequencies than smaller ones, which may be calculated. A 15" woofer narrows to 90° around 1 kHz, for example. For waveguides, pattern control is also related to size: larger ones control lower.

The larger 90° QSC waveguide has been measured by Augerpro (Brandon) and shown to begin losing pattern control at 2 kHz, and by 1 kHz, it's effectively not constant directivity, i.e., not a good match for a 15" woofer. None of this precludes anyone from building with this combination, and several have; it's just that smaller 12" woofers are a more optimum combination.

Next consideration is how low the compression driver will play in combination with how low the waveguide "loads" it. Generally, I try not to exceed the manufacturer's minimum crossover frequency specification, but many argue that those specs are for pro audio use, and there is considerable leeway for home use with derated SPL. This varies with each compression driver/waveguide combination, and the determination is best made using measurements. DE250 is rated at minimum 1.5 kHz, for example, but Geddes runs it on his 15" woofer/waveguide systems below 1 kHz.

Finally, is how HIGH the woofer will play competently, and it's a rare 15" that is well behaved above 1.5 kHz. There are exceptions to all of this, but in the extremes of these tradeoffs, some designs are simply not viable....

Great explanation Zilch. My interest would be the PA255-8 10" and I'd probably want to try it with the D220Ti CD because I want to spend less before I know if I like them (assume they will sound "good enough" to get me to move up).

[ttan98]

Re: Flex Your PCD Mettle:

I am looking for a high quality 10" driver to match my DE250 and horn combo similar to what is Harebrain already found. One 10" model which recently receives rave reviews is from Parker Audio's Excalibur model. It uses a 10" PSX Poly Cone. Recently I asked the designer where this driver came from, he declined to reveal the secret.

Anyone has any idea what this driver comes from? I am interested.

[danklugherz]

Re: Flex Your PCD Mettle:

I've shown two QSC waveguides in this thread, the 14" x 10" 152i, and now this 10.25" 122i.

A prime objective of EconoWave design is matching directivities of the woofer and waveguide in the crossover region. Larger woofers have narrower dispersion at these frequencies than smaller ones, which may be calculated. A 15" woofer narrows to 90° around 1 kHz, for example. For waveguides, pattern control is also related to size: larger ones control lower.

The larger 90° QSC waveguide has been measured by Augerpro (Brandon) and shown to begin losing pattern control at 2 kHz, and by 1 kHz, it's effectively not constant directivity, i.e., not a good match for a 15" woofer. None of this precludes anyone from building with this combination, and several have; it's just that smaller 12" woofers are a more optimum combination.

Next consideration is how low the compression driver will play in combination with how low the waveguide "loads" it. Generally, I try not to exceed the manufacturer's minimum crossover frequency specification, but many argue that those specs are for pro audio use, and there is considerable leeway for home use with derated SPL. This varies with each compression driver/waveguide combination, and the determination is best made using measurements. DE250 is rated at minimum 1.5 kHz, for example, but Geddes runs it on his 15" woofer/waveguide systems below 1 kHz.

Finally, is how HIGH the woofer will play competently, and it's a rare 15" that is well behaved above 1.5 kHz AND delivers extended bass. There are exceptions to all of this, but at the extremes of these tradeoffs, some designs are simply not viable....

Thanks Zilch, That's the info I was looking for. BTW I was referring to the 152i horn.

[A9X]

Re: Flex It Round #3.1 - EconoWave Delite 10e:

Original large Advent gets QSC 122i 10.25" axisymmetric waveguide and split speaker ring w/T-nuts to mount Eminence Deltalite II 2510:

Looking forward to seeing how this comes out. What CD are you using?

[Pete Schumacher]

Re: Flex Your PCD Mettle:

Great explanation Zilch. My interest would be the PA255-8 10" and I'd probably want to try it with the D220Ti CD because I want to spend less before I know if I like them (assume they will sound "good enough" to get me to move up).

With the published sensitivity of the PA255-8, the WG loaded RS28F might make an ideal match as well, after baffle step is considered.